1 894. 



CELL-DIVISION. 



423 





-—\ 



OirogoTieQ. 



v. Zone of 

 ^ Germination. 



/\. A 



Otfocyte I. 



1 



•-/ 





Zone of 

 Growth. 



Oirocyl-e JT- 



/ \ . 



Ovttnt- . 



/\ 





Zone of 

 Maturation. 



2nd Polar Bodv 



Diagram Showing the Development of the Egg- 

 Cells IN AscARis megalocephala (after Boveri). 



Primitive Germ-cell. 



Spermato- 

 fortes 



/ • • 9 ^9 



/I /\/\ l\ 



i 



\ Zone of 

 Germination. 



SpCi'ma.tocyte I _ 

 Spermatoeytell. .^ 



Spefmaiid.- - 



/\ l\ 



Zone of 

 r Growth. 



Zone of 

 Maturation. 



Spermatocyte I. = Sperm-grandmother-cell. 

 Spermatocyte II. = Sperra-mother-cell. 

 Spermatid = Spermatozoon. 



Diagram Showing the Development of the Sperm 

 Cells in Ascaris megalocephala [after Boveri). 



